public interface Penis {
　　public String getPenisSize();
}
public abstract class Man implements Penis{}
public class Takeshi extends Man {
　　public String getPenisSize() { return "大きい";}
}
public class Masaru extends Man {
　　public String getPenisSize() { return "小さい";}
}
public class Woman {
　　public void sex( Penis p ) { System.out.println( "あなたの ちんこ" + p.getPenisSize() + "のね" ); }
}
Woman woman = new Woman();
woman.sex( new Takeshi() );
woman.sex( new Masaru() );